1. Field of the Invention
The present invention refers to a separator element for use in a device for separating water and contaminants from fluids, comprising a hollow filter body, which is adapted to be arranged within a coalescence element of said device, which is provided with a first hydrophobic filter layer surrounding an inner flow chamber, and which, when installed in said device, is surrounded by an outer flow chamber around which the coalescence element is arranged, one end face of the filter body being closed and the other end face being provided with a flow opening.
2. Description of the Prior Art
Separator elements are used for removing from fluids, in particular from liquids and gases, such as aviation fuels and natural gases, water and contaminants.
The permit for known separator elements is normally limited to a structural design adapted to be used for a specific API class, i.e. the respective separator element can only be used within a predetermined range. For example, separator elements used in mobile fields have to remove 0.5% by weight of water, separator elements used in stationary fields have to remove 3% by weight of water and separator elements used in process fields have to remove 10% by weight of water from liquids which are virtually immiscible with water, or rather they have to reduce the water content of such liquids. However, none of the separator elements used in process fields or in stationary fields reaches the separating accuracy of the elements used in mobile fields. Up to now, it has been absolutely impossible to use separator elements in fields with highly alternating loads.
A separator element of the type mentioned at the beginning is known from EP 60 106 B1. This publication describes in detail a separator element in the form of a surface tension separator arranged within a device for separating water and contaminants from fluids. This separator is supposed to provide the possibility of separating -- after several separations of larger particles of water -- perhaps still existing finer particles of water from the fluid, said water particles being then discharged through a central opening into the bottom area of a container surrounding the separator.
However, devices for separating water and contaminants from fluids should fulfill the demand that water separation should be guaranteed also in the case of extreme alternating loads, i.e., constantly varying amounts of water, so that the perfect function of the units following said devices is not impaired for achieving thus optimum rates of utilization, economic efficiency and functional reliability.
The hitherto known filter elements endeavor to keep water separation constant in the case of different water rates, but it is often impossible to fulfill this demand in the case of varying loads and in particular in the case of extreme loads.
As will especially be evident from FIG. 1 of EP 60 106 B1, the known device tries to solve this problem by enlarging the distance between a coalescence element and the separator element for achieving thus a high sedimentation of the water droplets. However, a satisfactory result cannot be achieved in the case of varying water loads.
Moreover, the device known from EP 60 106 B1 is additionally provided with guide and deflection means, which are, however, also unable to produce the desired effect.
Nor can the desired success be achieved by means of preceding filters and/or cyclones in this connection.
Furthermore, flow elements in the form of irregularly perforated tubes (DE-A-1 645 749 or DE-A-3 145 964) were installed in separator elements, and although it was thus possible to achieve a more uniform surface load, it was still not possible to obtain the desired separating performance in the case of varying water loads.
Although the above-mentioned measures increased the flow rate and improved the separation efficiency, there is still the problem that a satisfactory function cannot be guaranteed in the case of alternating loads occurring, on the one hand, as very small amounts of water and/or small or minute water droplets and, on the other hand, as large amounts of water, e.g., water contents which suddenly increase rapidly by a factor of 10 to 100 and more than that in comparison with the previously adjusted water load.
An additional problem is that, although it is possible to remove by means of the conventional separator elements a very high percentage of large amounts of water from the liquids to be treated, it is still not possible to fully separate such large amounts of water. For example, a 97 to 98% removal of water from liquids, which is a common percentage in process fields, will not under any circumstances be sufficient for using the thus purified liquids e.g., in the field of aircraft refueling.